Double hung windows known in the art comprise a pair of vertically translating window sashes. The window sashes slide about channels located alongside the window jambs of a window frame. Either sash can overlap the other sash to provide varying openings of the window. A window sash generally comprises, at its top end, a locking mechanism to engage the window sash in a stationary position along the window jambs. The window sashes may also be independently attached to a biasing mechanism, continuously pulling the window sashes upward. Another interesting feature of the double hung windows is provided by a pivoting mechanism, which allows for the window sashes to be inclined inwardly. This allows, for example, the maintenance and the cleaning of both faces of a window sash and glass panel from the inside.
Pivot assemblies have been provided to achieve this pivoting while enabling the sliding of the window sash within the channels of the window jambs. The pivoting feature for inclining window sashes is allowed by pivoting mechanisms enclosed within the pivot assemblies.
Different models of pivot assemblies have been introduced with various options. U.S. Pat. No. 5,127,192, issued on Jul. 7, 1992 to Cross discloses a pivot assembly defining a housing which slides in a track and receives a rotor. The rotor is rotatively connected to a sash pivot, thus permitting the inclination of the window sash about the window jambs. Furthermore, the rotation of the rotor engages the housing in arresting contact with the track for preventing the housing to move along the track when the sash is rotated. This feature allows for the window sash to have a stationary pivoting axis between the window jambs.
It is known from U.S. Pat. No. 5,127,192 to provide an obstruction block for locking the window sash in the housing. The obstruction block closes a slot that provides an outlet for removing the window sash from the housing. In order to pull the window sash out of the housing, the obstruction blocks must be taken off. To do so, a screwdriver or the like is needed to release the obstruction block from the housing. This renders the removal of the window sash from the housing inconvenient. It also involves a risk of losing the obstruction blocks and making the assembly insecure.
Furthermore, U.S. Pat. No. 5,127,192 has not foreseen the risk of longitudinal dislocation of the sash pivots. Although the sash pivot is secured laterally in the rotor, the sash pivot is free to slide out of the rotor longitudinally. During transportation and installation of the window sash, the deflection or bowing of the frame may lead to such longitudinal dislocation.
U.S. Pat. No. 5,243,783, issued on Sep. 14, 1993 to Schmidt et al. provides improvements as it involves a pivot assembly comprising a pivot with a flange at an end thereof enclosed in a housing also comprising flanges. This configuration prevents the longitudinal dislocation aforementioned.
U.S. Pat. No. 5,243,783 also discloses a slot in the pivot rotor for removing the window sash from the housing. In this case, the slot is blocked by a retainer spring, having an end fixedly attached to the housing and an opposed free end obstructing the slot. The pivot of the window sash is inserted into the slot by depressing the free end of the retainer spring. The retainer spring resiliently moves back over the slot, thereby preventing the pivot from slipping out of the slot. To remove the window sash pivot from the slot, the retainer spring must be manually pushed inwardly. This makes the removal of the window sash from the pivot assembly intricate as a person can only remove one side of the window sash at a time, for the retainer spring must be pushed manually.
The removal of the window sash, one side at a time, causes further problems. When only one side of the window sash is released from the pivot assemblies, the window sash is tilted from its normal perpendicular position about the window jambs. In doing so, the flanges of the pivot tend to engage and pry against the flanges of the housing. This prying sometimes causes a portion of the flanges of the housing to crack off. Parts of the pivot assembly must then be replaced, thus increasing material costs and installation time.
Furthermore, a cantilever-like retainer spring such as disclosed in U.S. Pat. No. 5,243,783 must be of low stiffness to be pressed in manually. Consequently, such springs are not a reliable and durable solution.
U.S. Pat. No. 5,924,243, issued on Jul. 20, 1999 to Polowinczak et al. introduces a pivot assembly including a rotor rotatably disposed therein. The rotor comprises slots for receiving a pivot connected to a window sash. The slots are for receiving the pivot and a collar is located adjacent an end thereof. The slots comprise angled surfaces in order to provide the pivot and the collar with clearance in order to be released from the rotor without prying flanges at an opening of the rotor, as described previously. The collar also prevents the longitudinal dislocation of the window sash from the rotor in case of bowing of the window frame during transportation and installation.
The pivot assembly of U.S. Pat. No. 5,924,243 also defines a slot for releasing the window sash therefrom. A spring may be releasably installed on the lateral walls defining the slot in order to obstruct the slot. To remove the window sash pivot from the rotor, the spring must be removed beforehand, thereby rendering this operation inconvenient. If the spring is not used, the window sash is no longer secured in the rotor when tilted horizontally and may fall out.
It would be desirable to provide a window sash pivot assembly combining the advantages described above, while encompassing the problems found in the prior art. It would be of further interest to provide a window sash pivot assembly proposing a simple method for releasing the window sash therefrom. Furthermore, adding the durability and ease of assembly and repair features to such a system while keeping it inexpensive will be a step forward in the conception of window sash pivot assemblies.